The present invention relates to controllers for electrostatic precipitators and, in particular, to a controller employing a processing means for storing data.
Known power controllers for electrostatic precipitators measure an operating parameter such as the voltage and/or current at the precipitator. These measured parameters are used to control the power applied to the precipitator. These known controllers employ a microcomputer to measure operating parameters at successive times in a power cycle. Such systems record the measured parameters for subsequent control of the precipitator. See for example U.S. Pat. No. 4,290,003.
Effectively regulating a precipitator with a microcomputer requires assembling data and reacting to its significance. The control points for a precipitator should at times be changed based upon the past experience of the system. Also required for effective control is performance data occurring during a spark. Data thus assembled can be used to compare operation before during and after a spark.
Known microcomputers have interrupt lines, which are triggered by an external process such as the receipt of a message on a communications port. Signalling on an interrupt line can interrupt the main program currently running on the microcomputer. Once interrupted, an interrupt handler, software, diverts the microcomputer to the needs of the interrupting process.
Known precipitator controllers employ integrating circuits to obtain an average of time varying measurements. The additional circuitry, including relatively bulky and expensive capacitors, in electronic integrators lessens system reliability.
Effective control of a bank of precipitators requires detailed information on the operational parameters of each precipitator. Often an upstream precipitator will respond early to a change in gas entering that precipitator. This advance event can alert a downstream precipitators to expect changing gas characteristics.
Accordingly, there is a need for an improved precipitator controller that can act effectively by assembling as much data as necessary to react to its changing environment.